New module 'mbsspn'.

[gnulib.git] / lib / mbsspn.c

diff --git a/lib/mbsspn.c b/lib/mbsspn.c
new file mode 100644 (file)
index 0000000..f25c909
--- /dev/null
+++ b/lib/mbsspn.c
@@ -0,0 +1,97 @@
+/* Searching a string for a character outside a given set of characters.
+   Copyright (C) 1999, 2002, 2006-2007 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2007.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <string.h>
+
+#if HAVE_MBRTOWC
+# include "mbuiter.h"
+#endif
+
+/* Find the first occurrence in the character string STRING of any character
+   not in the character string REJECT.  Return the number of bytes from the
+   beginning of the string to this occurrence, or to the end of the string
+   if none exists.  */
+size_t
+mbsspn (const char *string, const char *reject)
+{
+  /* Optimize two cases.  */
+  if (reject[0] == '\0')
+    return 0;
+  if (reject[1] == '\0')
+    {
+      unsigned char uc = (unsigned char) reject[0];
+
+#if HAVE_MBRTOWC
+      if (MB_CUR_MAX > 1)
+       {
+         mbui_iterator_t iter;
+
+         for (mbui_init (iter, string); mbui_avail (iter); mbui_advance (iter))
+           if (!(mb_len (mbui_cur (iter)) == 1
+                 && (unsigned char) * mbui_cur_ptr (iter) == uc))
+             return mbui_cur_ptr (iter) - string;
+         return strlen (string);
+       }
+      else
+#endif
+       {
+         const char *ptr;
+
+         for (ptr = string; *ptr != '\0'; ptr++)
+           if ((unsigned char) *ptr != uc)
+             break;
+         return ptr - string;
+       }
+    }
+  /* General case.  */
+#if HAVE_MBRTOWC
+  if (MB_CUR_MAX > 1)
+    {
+      mbui_iterator_t iter;
+
+      for (mbui_init (iter, string); mbui_avail (iter); mbui_advance (iter))
+       {
+         if (mb_len (mbui_cur (iter)) == 1)
+           {
+             if (mbschr (reject, (unsigned char) * mbui_cur_ptr (iter)) == NULL)
+               return mbui_cur_ptr (iter) - string;
+           }
+         else
+           {
+             mbui_iterator_t aiter;
+
+             for (mbui_init (aiter, reject);
+                  mbui_avail (aiter);
+                  mbui_advance (aiter))
+               {
+                 if (!mbui_avail (aiter))
+                   return mbui_cur_ptr (iter) - string;
+                 if (mb_equal (mbui_cur (aiter), mbui_cur (iter)))
+                   break;
+               }
+           }
+       }
+      return strlen (string);
+    }
+  else
+#endif
+    return strspn (string, reject);
+}